Ok, I've been running, off and on, for a few years now. Not very fast, not very much, but whatever.
Now, I find myself having to do two (and sometimes four!) fast 20-minute bike rides per day. I'm really hurrying for at least half of these rides (school run, running late), and I have at least one extra child on the bike.
I'm finding I'm running slower, and wanting to run less often. I suspect my aerobic fitness is improving (it has to, right?), but I'd like to keep running, really.
Last Friday was my first try at doing four 20-minute rides, and I was completely knackered, and kinda blown for the weekend. Is that normal? If I persevere, will it improve?